The goal of the proposed project is to naturalistically investigate the roles assumed by retarded children and their non-handicapped siblings interacting at home, focusing on the reciprocity of sibling roles and behaviors, the unique contributions of siblings to socialization, and the indirect effects of being a member of a sibling pair in which one child is retarded. Research proposed for Year 1 will focus on an examination of the in-home interactions of mentally retarded children and their older, children and their younger non-handicapped brothers and sisters. A multi-method approach will be utilized including the following: a) in-home observations of the sibling pairs in a semi-structured context in which both children are playing with a standard set of toys, b) naturalistic observations of the children at home, engaging in any activities they choose, c) a maternal interview, and d) a sibling interview. Research proposed for the third year focuses on the indirect effects of being a member of a sibling pair in which one child is retarded. Dr. Brody received his training in Educational Psychology at the University of Arizona. Dr. Stoneman was trained in developmental psychology at Peabody College, specializing in research in mental retardation. Both are currently on the faculty of the University of Georgia in the Department of Child and Family Development.